Networks of mineral-associated organic matter fractions in forest ecosystems

verfasst von

Bin Niu, Qiuyu Chen, Hongzhe Jiao, Xiaoqin Yang, Ming Shao, Jian Wang, Guicai Si, Tianzhu Lei, Yibo Yang, Gengxin Zhang, Georg Guggenberger

Abstract

Mineral-associated organic matter (MAOM), the largest soil carbon pool, is formed through a series of organo-mineral interaction mechanisms. However, different organo-mineral fractions relevant to specific stabilization mechanisms and their response to environmental variables are poorly understood, which hinders accurate prediction of MAOM preservation under climate change. We applied sequential chemical extraction to separate MAOM into different organo-mineral fractions. To assess of response of different organo-mineral fractions to climate change, alpine forest soils with high environmental sensitivity along a controlled environmental gradient were selected. Residual OM and weakly adsorbed OM were the primary organo-mineral fractions, accounting for approximately 45.1–67.7 % and 16.4–30.6 %, respectively, of the total organic carbon (TOC). Climate exerted considerable indirect effects on the preservation of organo-mineral fractions through weathering and edaphic and biotic variables. Moreover, organo-mineral fractions were closely associated with metal cations (mainly Fe³⁺/Al³⁺) and secondary minerals, forming complex networks. Water-soluble OM (WSOM), weakly adsorbed OM and Fe/Al oxyhydroxides-stabilized OM were tightly linked, occupying the central position of the networks, and were closely related to soil pH, moisture and prokaryotic composition, indicating that edaphic and biotic factors might play important roles in maintaining the network structure and topology. In addition, Fe/Al-OM complexes, oxyhydroxides-stabilized OM and residual OM in the network were greatly impacted by climate and weathering factors, including precipitation, temperature and the plagioclase index of alteration (PIA). The complex network among organo-mineral fractions sheds light on MAOM dynamic stabilization for better predicting MAOM preservation under climate change.

Organisationseinheit(en)

Institut für Bodenkunde

Externe Organisation(en)

Chinese Academy of Sciences (CAS)
Graduate University of Chinese Academy of Sciences
University of Manchester
China West Normal University

Typ

Artikel

Journal

Science of the Total Environment

Band

898

ISSN

0048-9697

Publikationsdatum

10.11.2023

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Environmental engineering, Umweltchemie, Abfallwirtschaft und -entsorgung, Umweltverschmutzung

Ziele für nachhaltige Entwicklung

SDG 13 – Klimaschutzmaßnahmen

Elektronische Version(en)

https://doi.org/10.1016/j.scitotenv.2023.165555 (Zugang: Geschlossen)